Cap-Du's All-Day Arrow Barrage

This one is really an Aggression deck masquerading as a Leadership deck, however it is good for both single and multi-player. Basically Steve Rogers reduces the cost to get Yondu out, then Captain America provides both a shield wall (pun intended) or Threat reduction when necessary because he can be stood twice a round with his ability. There is plenty of redundancy built into the deck with the attachments so there is lots of "I can do this all day" fodder.
Youndu doesn't take incidental damage from attacking, so it's just a matter of stacking attachments on him and keep standing him to attack with the Sky-Cycle, Get Ready, Inspiring Presence, and Command Teams. By end-game he can easily be standing 3-5 times and dealing 5-6 damage every time he attacks. The Ready for Action, second Mighty Avengers, and even Reinforced Suit could be cut if something better comes out.